1. The problem statement, all variables and given/known data The electric field strength across a typical cell membrane is about 107 N/C. Given this information, find the magnitude of the acceleration of a single charged Ca+1 ion as it penetrated throught the cell wall. Ignore any resistive forces. One atomic mass unit is 1.66 x 10-27 kg. 2. Relevant equations F = ma F=q0E 3. The attempt at a solution I was thinking of multiplying the charge with how many protons a Ca ion has so: F=q0E = (20[itex]\bullet[/itex]1.6*10-19C)(107 N/C) = 3.2*10-11 N Then I manipulated for acceleration in F=ma and got 1.93*1016 m/s? Is this the correct method for finding the magnitude of acceleration?